Dell Optiplex GX520 No Sound

I bought a refurbished Dell Optiplex GX520 for my Daughter's room as a Christmas gift. I installed Windows XP Pro. I could not get internet using the onboard internet jack so I used a CNET internet card I snagged from a Dell Dimension I had in the garage. Now the internet works but I have no sound and when I view the systems hardware there is no audio at all. Does anyone know how to fix this, which downloads I need? Thank you

 

I would look for a Service Tag number on a sticker on the case. All new Dell products have this information available and I would assume refurbished products have the same option.

If you go to the Dell support site, Drivers and Downloads section, you should be given the option to input a service tag to reach the appropriate drivers for the whole system. Download and install as needed. (There would probably be the ethernet controller or Lan drivers needed for the network connection also.)